Rudder and rudder-propeller combination



RUDDER AND RUDDER-PROPELLER COMBINATION Filed April 26, 1961 INVENTOR.

BAILEY R DAWES BY 8W two-DJ AT TORA/EVS United States Patent ()fitice 3,082,728 Patented Mar. 26, 1963 3,082,728 RUDDER AND RUDDER-PROPELLER COMBINATION Bailey P. Dawes, 2350 Mt. View-Stevens Creek Road, Los Altos, Calif. Filed Apr. 26, 1961, Ser. No. 105,610 2 Claims. (Cl. 114-166) This invention relates to rudders for water crafts and to a rudder-propeller combination.

One of the objects of the invention is the provision of a rudder adapted for use in combination with a screw propeller that enables greater efliciency in steering the boat than heretofore.

A further object of the invention is the provision of a screw propeller in combination with a rudder so combined on inboard hulls as to provide an immediate and far greater response by the boat or water craft on which it is used, then heretofore.

The conventional rudder on propeller driven boats and yachts comprises the vertically disposed blade rotatable about a vertical axis at the front end thereof, or the end nearest to the propeller, which blade is positioned aft of the propeller in a vertical plane common to the axis of rotation of the propeller. When the rudder is turned in any position (right or left) for steering the boat, the latter will continue to move bodily in the original direction before the turn is fully efiected, and the distance it so moves varies with the speed of the boat on its original course and at the time the rudder is swung. Inasmuch as a slow moving craft responds to the rudder more slowly than a fast moving craft, and inasmuch as a fast moving craft has greater inertia for carrying it farther in its original direction, points may occur where the speed of the craft when the rudder is operated may be substantially material.

By the use of the present invention, this loss in efficiency that is above noted is greatly reduced at all speeds of the craft (or propeller).

Other objects and advantages will appear in the de' scription and in the drawings.

FIG. 1 is a side elevational view, partly in section showing the combination in which the propeller is within the shell of the annular rudder.

FIG. 2 is a sectional view of the rudder of FIG. 1 with the rudder in a position for turning the boat to the right, and the arrows indicate the changed direction of flow of the water upon leaving the propeller.

FIG. 3 is a rear elevational view of the rudder of FIG. 1.

In detail, FIGS. 1, 2 and 3 show a conventional screw and is preferably just inside the leading portion of the rudder approximately on the vertical axis of the rudder p The rudder 25 is preferably externally cylindrical and of substantially uniform outside diameter from end to end, and the radially inwardly facing surfaces may be of progressively reduced diameter from the leading edge of the rudder, rearwardly, past the propeller, to provide a relatively long gradual bevel 26, and the major horizontal length of the rudder will extend rearwardly of the propeller, with the result that the entire propeller stream will be within the rudder even when the latter is turned, as seen in FIG. 2. The bevelled or tapered interior of the rudder may terminate short of the trailing edge, but extends past the propeller.

In the description and the claims, the words forward, forwardly, rear, rearwardly and words of similar import, are used with respect to the bow of the boat; hence, the forward or leading edge of the rudder is the edge or end nearest the bow, while the rear or trailing edge or end is the edge or end remote from the The propeller stream will be progressively restricted as it passes through the rudder, with a resultant progressive increase in its velocity.

It should be noted that the increase in the velocity of the propeller stream not only increases the eificiency of the rudder in the present arrangement but it increases the efliciency of the propeller due to the increased thrust from the propeller stream at the rear end of the rudder.

In FIG. 1 the rudder and propeller are protected by a skeg 27 depending from and carried by the hearing at the rear end of the propeller shaft 28.

The rudder post 29, is above the propeller and adjacent to the forward end of the rudder. The portion 30 exposed -to the water is formed with a sharp leading edge with flat sides extending divergently past the sides of the post and then rearwardly to increase the elficiency of the rudder.

The inside diameter of the rudder is sufficiently great to permit the rudder to be swung about the axis of the rudder post without striking the propeller, and the lower end of skeg 27 is at a level that it will not interfere with the swinging of the rudder.

Preferably, in the present structure, the rudder post is mounted in a universal self-aligning bearing 31 to enable tilting the rudder slightly so that the bottom side will be directed slightly upwardly at the end of a swinging movement of the rudder. For example, when the rudder 25 is in the position seen in FIG. 2, the rear discharge end will be tilted upwardly with the result that the hull will be banked at the turn with the stern depressed and the bow elevated, which is desirable.

I claim:

1. In combination with the hull of a boat having bow and stern ends and a longitudinally extending horizontal axis extending through said ends, a propeller below said stern directed rearwardly relative to said how for generating a rearwardly directed propeller stream for propelling said boat, a vertically extending rudder post rotatahly supported on said boat for rotation about its vertical axis; a tubular rudder on the lower end of said post providing a horizontally extending open ended passageway therethrough positioned to receive and confine a substantial portion of said propeller stream for passage of the latter therethrough, said rudder being rotatable with said rudder post about the vertical axis of the latter for deflecting the propeller stream adapted to pass through said passageway to one side or the other of said longitudinally extending horizontal axis, said rudder having a forward end portion at its end nearest the bow of said boat and said propeller being disposed within said forward end portion, the outer surface of said rudder being cylindrical and of uniform diameter from end to end thereof, the forward end of said rudder terminating in a relatively sharp edge, the inner surface of said rudder being of substantially uniformly decreasing diameter in direction away from said edge for the major portion of the length of said rudder.

2. In combination with a boat having a propeller thereon in a fixed position below the stern end thereof and rotatable about a generally horizontally extending axis; a substantially horizontally disposed, cylindrical, openended, tubular rudder, a rudder post rotatable about a vertical axis supporting said rudder in a position extending longitudinally of said boat with the said propeller positioned within the end of said rudder nearest the bow of the boat, the outer surface of said rudder being of uniform diameter from end to end thereof, the end edge of said rudder adjacent to said propeller being relatively thin, and the inner surface of said rudder being References Cited in the file of this patent UNITED STATES PATENTS 899,359 Wadagaki Sept. 22, 1908 2,601,837 Dean July 1, 1952 2,803,211 Erlbacher Aug. 57 

1. IN COMBINATION WITH THE HULL OF A BOAT HAVING BOW AND STERN ENDS AND A LONGITUDINALLY EXTENDING HORIZONTAL AXIS EXTENDING THROUGH SAID ENDS, A PROPELLER BELOW SAID STERN DIRECTED REARWARDLY RELATIVE TO SAID BOW FOR GENERATING A REARWARDLY DIRECTED PROPELLER STREAM FOR PROPELLING SAID BOAT, A VERTICALLY EXTENDING RUDDER POST ROTATABLY SUPPORTED ON SAID BOAT FOR ROTATION ABOUT ITS VERTICAL AXIS; A TUBULAR RUDDER ON THE LOWER END OF SAID POST PROVIDING A HORIZONTALLY EXTENDING OPEN ENDED PASSAGEWAY THERETHROUGH POSITIONED TO RECEIVE AND CONFINE A SUBSTANTIAL PORTION OF SAID PROPELLER STREAM FOR PASSAGE OF THE LATTER THERETHROUGH, SAID RUDDER BEING ROTATABLE WITH SAID RUDDER POST ABOUT THE VERTICAL AXIS OF THE LATTER FOR DEFLECTING THE PROPELLER STREAM ADAPTED TO PASS THROUGH SAID PASSAGEWAY TO ONE SIDE OR THE OTHER OF SAID LONGITUDINALLY EXTENDING HORIZONTAL AXIS, SAID RUDDER HAVING A FORWARD END PORTION AT ITS END NEAREST THE BOW OF SAID BOAT AND SAID PROPELLER BEING DISPOSED WITHIN SAID FORWARD END PORTION, THE OUTER SURFACE OF SAID RUDDER BEING CYLINDRICAL AND OF UNIFORM DIAMETER FROM END TO END THEREOF, THE FORWARD END OF SAID RUDDER TERMINATING IN A RELATIVELY SHARP EDGE, THE INNER SURFACE OF SAID RUDDER BEING OF SUBSTANTIALLY UNIFORMLY DECREASING DIAMETER IN DIRECTION AWAY FROM SAID EDGE FOR THE MAJOR PORTION OF THE LENGTH OF SAID RUDDER. 